Was anyone able to use the "in" operator of security predicate?  I tried it but got "not authorized" error.  The org has a single select picklist field Product_Line__c in the Opportunity object.  The User object has a multi-select picklist called Product_Line_Access__c.  I would like to grant access to opportunities by product line and each user may manage one product line or multiple product lines.  Here's the code I inserted in security predicate: 'Product_Line__c' in ["$User.Product_Line_Access__c"].  I was able to update the dataset without error message.  However, when i tried to access the dataset, I got not authorized error.  Thanks for sharing your experience!